The manufacturing of integrated circuits includes many processes such as deposition processes, chemical mechanical polish (CMP) processes, etching processes, and the like. To fine tune the processes, advanced process control (APC) is needed, so that the processes may be fine tuned to suit for different products, recipes, layers, production tools, and the like.
Due to the enormous number of combinations of different products, recipes, layers, and production tools, the number of APC model parameters that characterizing the respective APC models is also significant. Therefore, it is impossible to provide APC model parameters for all of the combinations. Accordingly, some products will not have APC model parameters for them to be processed by some production tools. This will cause un-balanced usage of the production tools since wafers will be dispatched to production tools that have already had APC model parameters for processing these wafers. Some of the production tools may have long queues of wafers waiting for them to process, while some other production tools may stay idle since these production tools do not have the required APC model parameters for them to process these wafers.
For a production tool to start processing wafers of certain products, initial APC model parameters need to be provided before they are updated with more accurate APC model parameters. Currently, the initial APC model parameters are estimated by engineers. Accordingly, the accuracy of the estimated APC model parameters is affected by the experience of the engineers. If the estimated APC model parameters are not correct, the resulting wafers will have poor quality, and the processed wafers may have to be scraped. In addition, the manual estimation of the APC model parameters requires significant amount of man power.